The partnership with an entire health system is a first for HealthTeacher. Its curriculum focuses on physical and mental health, nutrition, injury prevention, anatomy and the dangers of tobacco, alcohol and drug use. Educators decide which lessons to use and how to use them.

Providing the program is part of a $5 million, five-year commitment by Sisters of Mercy for health education.

"While our children must have a knowledge of the basics, it's critical we also educate them on how to lead healthy lives," said Lynn Britton, Sisters of Mercypresident and chief executive officer.

At Fifth Street Elementary School in Washington, Mo., first-graders in Erin Bauer's class came back in from morning recess. Rather than immediately starting a lesson plan, their next assignment was a minute of deep breathing.

The image of a blue ball was projected on the classroom's white board. As the ball grew larger, the children inhaled; as it grew smaller, they let the air out.

Bauer said the HealthTeacher deep breathing app seemed to be paying off.

"They do seem calmer, and they like it," she said.

Robert Bergamini, a pediatric oncologist at Mercy Children's Hospital in St. Louis, believes that programs like HealthTeacher can help in the battle against childhood obesity.

"Education worked to reduce smoking; it can do the same to improve children's health," Bergamini said.